The recent and unanticipated successes in both cloning sheep using nuclei from adult fibroblasts and in solving many forms of infertility by intracytoplasmic sperm injection (ICSI) now forces questions as to whether a combination of these approaches will result in reliable and efficient applications for propagating valuable research models, especially non-human primates. Spontaneous mutations resulting in unique animals to investigate diseases (e.g., retinitis pigmentosa) are periodically discovered in non-human primate colonies, and the ability to propagate these animals is vital for future investigations. While electrofusion of blastomere nuclei with enucleated rhesus oocytes resulted in two offspring (one male and one female) in 1996, last year=s attempts have not been successful. Intracytoplasmic nuclear injection (ICNI) holds bright promise as an alternative approach for propagating identical non-human primates. This project seeks to sequentially perfect IC NI c apabilities and develop new animal resources by addressing four specific aims. 1. Is intracytoplasmic sperm injection an effective and efficient method for propagating rhesus monkeys? 2. Is round spermatid injection (ROSI) an effective method for propagation? 3. Is intracytoplasmic nuclear injection, using blastomere nuclei obtained from rhesus monkey embryos injected into unfertilized enucleated oocytes, an effective and efficient method of propagation? 4. Is intracytoplasmic nuclear injection, using nuclei obtained from somatic cells cultured from adult and fetal rhesus tissues and injected into unfertilized enucleated oocytes, an effective and efficient method of propagation? ICNI may well find fantastic uses as a reliable, routine approach for propagating invaluable research animal resources of vital importance for the entire biomedical research community. FUNDING NIH R24 RR13632, HD18185 PUBLICATIONS Dominko T, Hewitson L, Simerly C, Luetjens M, Sutovsky P, Takahashi D, Schatten G. What is transferred during nuclear transfer? Imaging of mitochondrial, DNA, and centrosome dynamics in nuclear transfer rhesus embryos. Biol Reprod 58:99, 1998. Hewitson L, Takahashi D, Dominko T, Simerly CR, Schatten G. Assessing intracytoplasmic sperm injection Fertilization, embryo development, embryo transfer and pregnancy in the rhesus monkey. Fertil Steril 70:S242, 1998. Hewitson L, Takahashi D, Dominko T, Simerly C, Schatten G. Fertilization and embryo development to blastocysts after intracytoplasmic sperm injection in the rhesus monkey. Hum Reprod 13:3449-3455, 1998.